TW202132214A - Sulfide solid electrolyte - Google Patents

Abstract

The purpose of the present invention is to provide: a sulfide solid electrolyte that is capable of maintaining lithium ion conductivity and inhibiting generation of hydrogen sulfide gas; and an electrode composite material, a slurry, and a battery that use the sulfide solid electrolyte. In order to achieve the purpose, provided is a sulfide solid electrolyte containing the element lithium (Li), the element phosphorus (P), the element sulfur (S), at least one halogen (X) element, and a metal (M) element having a first ionization energy of more than 520.2 KJ/mol but less than 1007.3 KJ/mol, and including a crystal phase having a peak at the positions where 2[Theta] = 25.19 DEG ± 1.00 DEG and 29.62 DEG ± 1.00 DEG in an X-ray diffraction pattern as measured using CuK[alpha]1 rays.

Description

Sulfide solid electrolyte

The present invention relates to a sulfide solid electrolyte, and an electrode composite material, slurry and battery using the sulfide solid electrolyte.

The solid battery does not use a combustible organic solvent, so it can simplify the safety device. In addition to its excellent manufacturing cost and productivity, it also has the characteristics of being able to be laminated in series in the battery cell to achieve high voltage. . In the sulfide solid electrolyte used in the solid battery, no side reaction occurs due to the movement of anions, since none other than lithium ions move, and improvement in safety and durability can be expected.

As a sulfide solid electrolyte, it contains lithium (Li) element, phosphorus (P) element, sulfur (S) element and halogen (X) element, as well as sulfide containing a crystalline phase with Argyrodite crystal structure. Solid electrolytes are known (for example, Patent Document 1 to Patent Document 6). [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2016-024874 A [Patent Document 2] International Publication No. 2016/104702 [Patent Document 3] International Publication No. 2018/003333 [Patent Document 4] International Publication No. 2018/030436 [Patent Document 5] Japanese Patent Application Publication No. 2018-029058 [Patent Document 6] Japanese Patent Application Publication No. 2018-045997

[The problem to be solved by the invention]

Although the sulfide solid electrolyte has excellent lithium ion conductivity, it has high reactivity with moisture. Therefore, when a sulfide solid electrolyte is used to manufacture a lithium secondary battery, the sulfide solid electrolyte is in contact with the atmosphere and reacts with moisture in the atmosphere, which may generate toxic hydrogen sulfide gas or cause lithium ion conductivity. Reduced situation.

Therefore, the object of the present invention is to provide a sulfide solid electrolyte that can maintain lithium ion conductivity while suppressing the generation of hydrogen sulfide gas. In addition, an object of the present invention is to provide an electrode composite, slurry, and battery using the sulfide solid electrolyte. [Means to solve the problem]

The present inventors have discovered that lithium (Li) element, phosphorus (P) element, sulfur (S) element and halogen (X) element are contained in the X-ray diffraction pattern measured using CuKα1 line at 2θ= 25.19˚±1.00˚ and 29.62˚±1.00˚ in the sulfide solid electrolyte with the peak crystalline phase, by reducing a part of Li to have the first liberation of more than 520.2 KJ/mol and less than 1007.3 KJ/mol The replacement of the metal (M) element can maintain the lithium ion conductivity of the sulfide solid electrolyte before the replacement, and at the same time, it can suppress the generation of hydrogen sulfide gas more than the sulfide solid electrolyte before the replacement, thus completing the present invention .

That is, the present invention includes the following inventions. [1] A sulfide solid electrolyte characterized by: Contains: lithium (Li) element, phosphorus (P) element, sulfur (S) element, at least one halogen (X) element, at least one metal with a first free energy greater than 520.2 KJ/mol and less than 1007.3 KJ/mol (M) element, and, Contains: The X-ray diffraction pattern measured using CuKα1 line has a crystalline phase with peaks at 2θ=25.19˚±1.00˚ and 29.62˚±1.00˚. [2] An electrode composite material containing the sulfide solid electrolyte described in [1] above and an active material. [3] A slurry containing the sulfide solid electrolyte described in [1] above and a dispersion medium. [4] A battery comprising: a positive electrode layer, a negative electrode layer, and a solid electrolyte layer located between the positive electrode layer and the negative electrode layer, wherein the battery is characterized in that the solid electrolyte layer contains the solid electrolyte layer described in [1] above The sulfide solid electrolyte.

In addition, the "first dissociation energy" in the present invention is the same as the first dissociation energy described in "Schreiber Atkins" Inorganic Chemistry (Part 1)" 4th Edition "Part I" Fundamentals" 1. Atomic Structure", so the description is omitted here. In addition, the unit of the "first free energy" specified in the present invention is "KJ/mol", although it is the same as the unit of the first free energy described in "Schreiber Atkins" Inorganic Chemistry (Part 1)" 4th Edition Appendix 2" "EV" is different, but it can be converted as 1eV=96.485 KJ/mol. [Effects of the invention]

The present invention provides a sulfide solid electrolyte that can maintain lithium ion conductivity while suppressing the generation of hydrogen sulfide gas, and an electrode composite, slurry and battery using the sulfide solid electrolyte.

≪Sulfide solid electrolyte≫ The sulfide solid electrolyte of the present invention contains: lithium (Li) element, phosphorus (P) element, sulfur (S) element, at least one halogen (X) element, with a value greater than 520.2 KJ/mol and less than 1007.3 KJ/mol At least one metal (M) element of the first free energy. In addition, metal (M) elements with a first free energy greater than 520.2 KJ/mol and less than 1007.3 KJ/mol are sometimes referred to as "metal (M) elements" hereinafter.

At least one type of halogen (X) element may be one type of halogen (X) element, or two or more types of halogen (X) element. At least one halogen (X) element can be selected from fluorine (F) element, chlorine (Cl) element, bromine (Br) element and iodine (I) element. From the viewpoint of improving lithium ion conductivity, at least one halogen (X) element is preferably at least one of chlorine (Cl) element and bromine (Br). From the viewpoint of elasticity, two types of chlorine (Cl) element and bromine (Br) element are preferable.

The at least one metal (M) element may be one metal (M) element, or two or more metal (M) elements. The first free energy of metal (M) element is greater than 520.2 KJ/mol and less than 1007.3 KJ/mol. The first dissociation energy is the lowest energy required to take away an electron from the outermost layer of an atom. Since the Li ⁺ system has a small radius, it is easily stabilized by water and at the same time, because it is monovalent, the electrostatic attraction is small, so there is a tendency to reduce the lattice energy. Therefore, the Li ⁺ system tends to enhance the reactivity of the sulfide solid electrolyte with moisture. In contrast, metal (M) elements with a first free energy greater than 520.2 KJ/mol and less than 1007.3 KJ/mol are due to the formation of cations with a larger ion radius ^{than Li +, or the formation of higher valence} Large cations tend to weaken the reactivity of the sulfide solid electrolyte with moisture. Therefore, it contains lithium (Li) element, phosphorus (P) element, sulfur (S) element, and halogen (X) element, and has the X-ray diffraction pattern measured using CuKα1 line at 2θ=25.19˚±1.00 ˚ and 29.62˚±1.00˚ in the sulfide solid electrolyte with the peak crystalline phase, by adding a part of Li to the metal ( The substitution of M) elements can maintain the lithium ion conductivity of the sulfide solid electrolyte before the substitution, and at the same time, it can suppress the generation of hydrogen sulfide gas more than the sulfide solid electrolyte before the substitution. The first free energy of the metal (M) element is not particularly limited as long as it is 520.2 KJ/mol and less than 1007.3 KJ/mol. However, it maintains the lithium ion conductivity of the sulfide solid electrolyte before the substitution, and at the same time, it is higher than that before the substitution. From the standpoint that the sulfide solid electrolyte can more effectively suppress the generation of hydrogen sulfide gas, 540 KJ/mol or more and 1000 KJ/mol or less is preferable, and 560 KJ/mol or more and 800 KJ/mol or less is more preferable.

The valence of the cation formed by the metal (M) element is usually 1, 2 or 3, and 3 is preferred. The greater the valence of the cation formed by the metal (M) element, the greater the lattice energy and the better the water resistance of the sulfide solid electrolyte. Therefore, the sulfide solid electrolyte can hardly react with moisture, and the generation of hydrogen sulfide gas can be more effectively suppressed.

As the metal (M) element, for example, silver (Ag) element, magnesium (Mg) element, calcium (Ca) element, yttrium (Y) element, etc., are mentioned, but among these, the lithium ion conductivity is maintained while at the same time From the viewpoint of more effectively suppressing the generation of hydrogen sulfide gas, silver (Ag) element and yttrium (Y) element are preferable, and yttrium (Y) element is preferable. The first free energy of silver (Ag) element, magnesium (Mg) element, calcium (Ca) element and yttrium (Y) element are 731.0 KJ/mol, 737.3 KJ/mol, 589.6 KJ/mol and 615.6 KJ/mol, respectively .

In addition, the first group elements, namely hydrogen (H) element, lithium (Li) element, sodium (Na) element, potassium (K) element, rubidium (Rb) element, cesium (Cs) element and thium (Fr) element The first free energy is 1312.2 KJ/mol, 513.3 KJ/mol, 495.7 KJ/mol, 418.7 KJ/mol, 403.0 KJ/mol, 375.7 KJ/mol and 400.4 KJ/mol, and mercury (Hg) element The first free energy is 1007.3 KJ/mol. Therefore, the first group elements and mercury (Hg) elements are not equivalent to metal (M) elements.

The content of lithium (Li) element, phosphorus (P) element, sulfur (S) element, halogen (X) element, and metal (M) element in the sulfide solid electrolyte of the present invention is to maintain lithium ion conductivity while maintaining lithium ion conductivity. From the viewpoint of suppressing the generation of hydrogen sulfide gas, appropriate adjustments can be made.

From the viewpoint of improving lithium ion conductivity, the content of phosphorus (P) element is based on the total molar amount of the constituent elements of the sulfide solid electrolyte of the present invention, and is based on 7.4 mol% or more and 8.5 mol% or less Preferably, it is more preferably 7.6 mol% or more and 8.3 mol% or less, and more preferably 7.9 mol% or more and 8.2 mol% or less.

From the viewpoint of improving lithium ion conductivity, the ratio of the content of lithium (Li) element to the content of phosphorus (P) element, calculated in molar ratio, is preferably 2.0 or more and 6.5 or less, and 3.0 or more and 6.2 or less. Preferably, more than 4.0 and less than 5.8 are more preferable, and more than 4.6 and less than 5.5 are even more preferable.

From the viewpoint of improving lithium ion conductivity, the ratio of the content of sulfur (S) element to the content of phosphorus (P) element, calculated in molar ratio, is preferably 4.0 or more and 5.5 or less, and 4.1 or more and 5.3 or less. More preferably, more than 4.2 and less than 5.0 are more preferable, and more than 4.3 and less than 4.6 are even more preferable.

From the perspective of improving lithium ion conductivity, the ratio of the content of the halogen (X) element to the content of the phosphorus (P) element, calculated in molar ratio, is preferably 0.50 or more and 2.2 or less, and 0.80 or more and 2.0 or less. Preferably, 1.0 or more and 1.9 or less are more preferable, and 1.4 or more and 1.8 or less are even more preferable. In addition, when the sulfide solid electrolyte of the present invention contains two or more halogen (X) elements, "the content of the halogen (X) element" means the total content of the two or more halogen elements. This is the same throughout this manual.

From the viewpoint of maintaining lithium ion conductivity and effectively suppressing the generation of hydrogen sulfide gas, the ratio of the content of the metal (M) element to the content of the phosphorus (P) element, calculated in molar ratio, is more than 0 It is preferably 2.0 or less, preferably 0.02 or more and 0.85 or less, more preferably 0.04 or more and 0.75 or less, and still more preferably 0.08 or more and 0.65 or less. In addition, when the sulfide solid electrolyte of the present invention contains two or more metal (M) elements, "the content of the metal (M) element" means the total content of the two or more metal (M) elements. This is the same throughout this manual.

From the viewpoint of maintaining lithium ion conductivity while effectively suppressing the generation of hydrogen sulfide gas, the ratio of the total content of lithium (Li) and metal (M) elements to the content of phosphorus (P) is expressed in moles The ratio is calculated to be 2.2 or more and 6.7 or less, 4.4 or more and 6.2 or less, more preferably 4.8 or more and 5.8 or less, and 5.2 or more and 5.6 or less even more preferably.

From the viewpoint of maintaining lithium ion conductivity and effectively suppressing the generation of hydrogen sulfide gas, the ratio of the content of the metal (M) element to the content of the lithium (Li) element, calculated in molar ratio, is greater than 0 It is preferably 1.0 or less, preferably 0.001 or more and 0.6 or less, more preferably 0.005 or more and 0.3 or less, and even more preferably 0.01 or more and 0.2 or less.

When the sulfide solid electrolyte of the present invention contains chlorine (Cl) element and bromine (Br) element, the ratio of the content of chlorine (Cl) element to the total content of chlorine (Cl) element and bromine (Br) element is expressed as Mo The ear ratio calculation is preferably 0.1 or more and 0.9 or less, preferably 0.2 or more and 0.8 or less, and more preferably 0.3 or more and 0.7 or less.

The sulfide solid electrolyte system of the present invention may also contain impurities. The content of impurities, from the viewpoint of preventing adverse effects on the performance of the sulfide solid electrolyte of the present invention, is based on the total molar amount of the constituent elements of the sulfide solid electrolyte of the present invention, preferably less than 5 mol% , Less than 3 mol% is preferable, and less than 1 mol% is more preferable.

The molar amount of each element contained in the sulfide solid electrolyte is obtained by dissolving the sulfide solid electrolyte in an alkali solution, etc. AES) and other known methods can be measured.

The sulfide solid electrolyte of the present invention is based on the X-ray diffraction pattern measured using CuKα1 line, and has peaks at 2θ=25.19˚±1.00˚ and 29.62˚±1.00˚. The crystal phase derived from the above peak is sometimes referred to as the "crystal phase of the present invention" below. The sulfide solid electrolyte of the present invention may contain one type of crystal phase corresponding to the crystal phase of the present invention, or may contain two or more types of crystal phases corresponding to the crystal phase of the present invention. The crystalline phase of the present invention preferably has a pyrite type crystalline structure. The sulphur-germanite crystal structure is the crystal structure of the compound group derived from the mineral represented by the chemical formula: Ag _{8 GeS 6.} The sulphur-germanite crystal structure is preferably a cubic crystal system. Since the crystalline phase of the present invention has a pyrite type crystal structure, it can maintain ion conductivity while effectively suppressing the generation of hydrogen sulfide. In other words, one of the characteristics of the present invention is that the crystalline phase of the present invention is a sulfide solid electrolyte having a sulfide-germanite crystal structure, and a particularly ideal metal element is newly discovered. For example, in a sulfide solid electrolyte made of glass ceramics, since it undergoes a process of uniformly dispersing metal elements through vitrification, it is considered that no matter what kind of metal element is easy to replace, it is In the sulphur-germanite crystal structure produced by the reaction, the substitution can be promoted only in the case of specific metal elements.

The sulfide solid electrolyte of the present invention may be composed of the crystalline phase of the present invention, or may be composed of the crystalline phase of the present invention and one or more other phases. The other phases may be crystalline phases or amorphous phases. Examples of other phase systems include Li ₂ S phase, LiCl phase, LiBr phase, Li ₃ PS ₄ phase, and LiCl _1-a Br _a (0<a<1). When the sulfide solid electrolyte of the present invention is composed of the crystalline phase of the present invention and one or two or more other phases, the main phase of the crystalline phase system of the present invention is preferred. The "main phase" refers to the phase having the largest ratio based on the total amount of all crystal phases constituting the sulfide solid electrolyte of the present invention. The ratio of the crystalline phase of the present invention contained in the sulfide solid electrolyte of the present invention is based on all the crystalline phases constituting the sulfide solid electrolyte of the present invention, and is preferably 60% by mass or more, and 70% by mass or more. Preferably, 80% by mass or more is more preferable, and 90% by mass or more is even more preferable. In addition, the ratio of the crystalline phase can be confirmed by, for example, X-ray diffraction (XRD).

In one embodiment, the sulfide solid electrolyte of the present invention has a composition represented by the following formula (I): Li _a M _b PS _c X _d ···(I) [where X is at least one halogen (X) Element, M is at least one metal (M) element, a is 3.0 or more and 6.5 or less, b is more than 0 and 6.5 or less, c is 3.5 or more and 5.5 or less, and d is 0.50 or more and 3.0 or less].

X is at least one halogen element selected from fluorine (F) element, chlorine (Cl) element, bromine (Br), and iodine (I) element. The iodine (I) element system has a tendency to reduce lithium ion conductivity, and the fluorine (F) element system is difficult to introduce into the crystal structure. Therefore, X is preferably at least one halogen element selected from the chlorine (Cl) element and the bromine (Br) element.

From the viewpoint of improving the lithium ion conductivity of the sulfide solid electrolyte of the present invention, the a is preferably 3.0 or more and 6.5 or less, preferably 3.5 or more and 6.3 or less, and more preferably 4.0 or more and 6.0 or less. By setting a to 3.0 or more, the amount of Li in the crystal structure can be suppressed from decreasing, and as a result, the decrease in lithium ion conductivity can be suppressed. On the other hand, by setting a to 6.5 or less, it is possible to suppress the decrease of the pores of Li crystal sites, and as a result, it is possible to suppress the decrease of the lithium ion conductivity.

From the viewpoint of improving the lithium ion conductivity of the sulfide solid electrolyte of the present invention, the b is preferably 0.010 or more and 3.0 or less, preferably 0.050 or more and 1.5 or less, and more preferably 0.080 or more and 0.80 or less.

From the viewpoint of improving the lithium ion conductivity of the sulfide solid electrolyte of the present invention, the c system is preferably 3.5 or more and 5.5 or less, preferably 4.0 or more and 5.3 or less, and more preferably 4.2 or more and 5.0 or less.

From the viewpoint of improving the lithium ion conductivity of the sulfide solid electrolyte of the present invention, d is preferably 0.70 or more and 2.8 or less, preferably 0.90 or more and 2.4 or less, and more preferably 1.1 or more and 1.8 or less.

In formula (I), a part of P can also be derived from silicon (Si) element, germanium (Ge) element, tin (Sn) element, lead (Pb) element, boron (B) element, aluminum (Al) element, Replaced by one or more elements selected from gallium (Ga) element, arsenic (As) element, antimony (Sb) element and bismuth (Bi) element.

The sulfide solid electrolyte of the present invention contains the crystalline phase of the present invention, which can be confirmed by the X-ray diffraction pattern measured using CuKα rays. As the CuKα wire system, for example, CuKα1 wire can be used.

The sulfide solid electrolyte of the present invention is based on the X-ray diffraction pattern measured using CuKα1 line, and preferably has peaks at the positions of 2θ=25.19˚±1.00˚ and 29.62˚±1.00˚. These peaks are the peaks derived from the crystal phase of the present invention.

In this specification, the term "peak" mainly means the apex of the peak. In the X-ray diffraction pattern, whether there is a peak in each range can be determined as follows. For example, the peak value at the position of 2θ=25.19˚±1.00˚ is in the X-ray diffraction pattern, and 2θ=(25.19˚-1.0˚)±0.5˚, that is, 2θ=24.19˚±0.5˚, And 2θ=(25.19˚＋1.0˚)±0.5˚, that is, the average value of 2θ=26.19˚±0.5˚ X-ray intensity (counts) is regarded as the background (BG) intensity A, taking 25.19˚±1.0˚ When the maximum value of the X-ray intensity (counts) is regarded as the peak intensity B, if the ratio (B/A) is 1.01 or more, preferably 1.05 or more, more preferably 1.10 or more, it can be judged as 2θ=25.19˚± There is a peak at the position of 1.00˚. The same is true when determining whether other peaks exist in the predetermined position. In addition, the above-mentioned X-ray intensity is the value measured by the apparatus and conditions used in the Example mentioned later.

The sulfide solid electrolyte of the present invention is based on the X-ray diffraction pattern measured by using CuKα1 line. In addition to the positions of 2θ=25.19˚±1.00˚ and 29.62˚±1.00˚, it is also determined by 2θ=15.34˚±1.00 ˚, 17.74˚±1.00˚, 30.97˚±1.00˚, 44.37˚±1.00˚, 47.22˚±1.00˚ and 51.70˚±1.00˚, it is better to have peaks at 1 or more of the selected positions; except for 2θ= In addition to the positions of 25.19˚±1.00˚ and 29.62˚±1.00˚, it is better to have peaks at all positions of 2θ=30.97˚±1.00˚, 44.37˚±1.00˚ and 47.22˚±1.00˚; except for 2θ=25.19 In addition to the positions of ˚±1.00˚ and 29.62˚±1.00˚, in all positions of 2θ=15.34˚±1.00˚, 17.74˚±1.00˚, 30.97˚±1.00˚, 44.37˚±1.00˚ and 47.22˚±1.00˚ It is better to have a peak value on the upper side; in addition to the positions of 2θ=25.19˚±1.00˚ and 29.62˚±1.00˚, 2θ=15.34˚±1.00˚, 17.74˚±1.00˚, 30.97˚±1.00˚, 44.37˚± It is better to have peaks at all positions of 1.00˚, 47.22˚±1.00˚ and 51.70˚±1.00˚. These peaks are the peaks derived from the crystal phase of the present invention.

In addition, although the peak position is represented by the central value ±1.00˚, the central value ±0.500˚ is better, and the central value ±0.300˚ is better.

The form of the sulfide solid electrolyte of the present invention is, for example, a powder form. _{The median diameter D 50} of the sulfide solid electrolyte of the present invention can be adjusted appropriately. _{The median diameter D 50} of the sulfide solid electrolyte of the present invention is preferably 0.1 μm or more and 100 μm or less, and preferably 0.2 μm or more and 10 μm or less. In addition, the median diameter D ₅₀ is the particle size at which the cumulative volume is 50% in the volume-based particle size distribution of the powder measured by the laser diffraction scattering particle size distribution measurement method.

≪Manufacturing method of sulfide solid electrolyte≫ The production method of the sulfide solid electrolyte of the present invention is not particularly limited. A manufacturing method capable of obtaining the desired sulfide solid electrolyte described above is preferable, and a known manufacturing method can be used. In addition, the manufacturing method of the sulfide solid electrolyte of the present invention is described in the examples, and therefore the description is omitted here.

≪Electrode composite material≫ The electrode composite material of the present invention contains the sulfide solid electrolyte of the present invention and an active material.

In one embodiment, the electrode composite material of the present invention is a negative electrode composite material. When the active material is a negative electrode active material, the electrode composite material of the present invention becomes a negative electrode composite material.

Examples of the negative electrode active material system include carbon materials, metal materials, and the like. Among these, one kind may be used alone or two or more kinds may be used in combination. Carbon materials or metal materials are general materials listed as negative electrode active materials, and therefore description thereof is omitted here. The negative active material is preferably electronically conductive.

The blending ratio of the sulfide solid electrolyte of the present invention and the negative electrode active material (the sulfide solid electrolyte of the present invention: the negative electrode active material) can consider capacitance, electronic conductivity (electron conduction path), and ion conductivity (ion conduction). Path) and make appropriate adjustments. The blending ratio of the sulfide solid electrolyte and the negative electrode active material of the present invention, in terms of mass ratio, is preferably 95:5-5:95, preferably 90:10-10:90, and 85:15-15 : 85 is better.

The negative electrode composite system may also contain a conductive auxiliary agent. When the electron conductivity of the negative electrode active material is low, it is preferable that the negative electrode composite material contains a conductive auxiliary agent. The conductive auxiliary agent is not particularly limited as long as it has lithium ion conductivity, but the electronic conductivity is preferably 1×10 ³ S/cm or more, preferably 1×10 ⁵ S/cm or more. As the conductive auxiliary agent system, general materials can be suitably used, so the description is omitted here. In addition, the content of the conductive auxiliary agent can be appropriately adjusted in consideration of capacitance, electron conductivity (electron conduction path), ion conductivity (ion conduction path), etc., and is not particularly limited.

The negative electrode composite material can also contain the binder needed to make the negative electrode active material and the solid electrolyte tightly bond with each other. As the binder system, general materials can be suitably used, so the description is omitted here.

The negative electrode composite material can be manufactured by mixing, for example, a sulfide solid electrolyte, a negative electrode active material, and optionally a conductive assistant and/or a binder. The mixing system can be carried out using, for example, a mortar, a ball mill, a bead mill, a jet mill, a planetary ball mill, a vibratory ball mill, a sand mill, and a twist mill. The mixing system can also be performed in a dry type or a wet type, but it is better to perform it in a wet type. The solvent used in the wet process is preferably an organic solvent.

In another embodiment, the electrode composite material of the present invention is a positive electrode composite material. When a positive electrode active material is used as the active material, the electrode composite material of the present invention becomes a positive electrode composite material. The positive electrode composite material can be obtained by blending the sulfide solid electrolyte of the present invention and the positive electrode active material.

The positive electrode active material is a material capable of inserting and desorbing lithium ions, and can be appropriately selected from known positive electrode active materials. Examples of the positive electrode active material system include metal oxides and sulfides. Examples of the metal oxide system include transition metal oxides.

The positive electrode composite system may also contain a conductive auxiliary agent. The description of the conductive aid is the same as that of the negative electrode composite material.

The description of the blending ratio of the sulfide solid electrolyte and the positive electrode active material of the present invention and the method for producing the positive electrode composite material are the same as those of the negative electrode composite material.

≪Slurry≫ The slurry of the present invention contains the sulfide solid electrolyte of the present invention and a dispersion medium.

The content of the sulfide solid electrolyte of the present invention in the slurry of the present invention can be appropriately adjusted according to the use of the slurry of the present invention. The slurry of the present invention can have various viscosities according to the content of the sulfide solid electrolyte of the present invention, and can have various forms such as ink or paste according to the viscosity. The slurry of the present invention can be used in the manufacture of the battery of the present invention. The content of the sulfide solid electrolyte of the present invention in the slurry of the present invention is based on the total mass of the slurry of the present invention, preferably from 10% by mass to 90% by mass, and from 20% by mass to 80% by mass. It is more preferably 30% by mass or more and 70% by mass or less.

The dispersing medium contained in the slurry of the present invention is not particularly limited as long as it can disperse the sulfide solid electrolyte of the present invention. As a dispersion medium system, water, an organic solvent, etc. are mentioned, for example. The dispersing medium can also be one solvent, or a mixture of two or more solvents.

≪Battery≫ The battery of the present invention includes a positive electrode layer, a negative electrode layer, and a solid electrolyte layer located between the positive electrode layer and the negative electrode layer, and the solid electrolyte layer contains the sulfide solid electrolyte of the present invention.

The battery of the present invention is preferably a solid battery, and preferably a lithium solid battery. The lithium solid battery may be a primary battery or a secondary battery, but a lithium secondary battery is preferred. A solid battery is a solid battery that does not contain any liquid or gel material as an electrolyte, but also includes, for example, a liquid material or gel material that contains 50% by mass or less, 30% by mass or less, and 10% by mass or less. The state of the electrolyte. Examples of the form of the solid battery include a laminated type, a cylindrical type, and a square type.

The positive electrode layer is a layer containing a positive electrode active material, and preferably a layer containing the positive electrode composite material of the present invention. The thickness of the positive electrode layer is preferably 0.01 mm or more and 10 mm or less. As a method of manufacturing the positive electrode layer, the same method as a known method can be used.

The negative electrode layer is a layer containing a negative electrode active material, and preferably a layer containing the negative electrode composite material of the present invention. The thickness of the negative electrode layer is preferably 100 nm or more and 5 mm or less, preferably 1 μm or more and 3 mm or less, and more preferably 5 μm or more and 1 mm or less. As a manufacturing method of the negative electrode layer, the same method as a well-known method can be used.

The electrolyte layer is a layer containing the sulfide solid electrolyte of the present invention. The electrolyte layer system may contain solid electrolytes other than the sulfide solid electrolyte of the present invention. The electrolyte layer may also contain a binder. As the binder, the same binder as that of the negative electrode composite material of the present invention can be used. The thickness of the electrolyte layer is preferably 0.001 mm or more and 1 mm or less. As a manufacturing method of the electrolyte layer, the same method as a well-known method can be used.

The battery of the present invention is preferably further equipped with a current collector.

The battery of the present invention can be manufactured by joining each member. As a joining method, the same method as a well-known method can be used. [Example]

[Example 1] (1) The production of a sulfide solid electrolyte was composed of Li _4.8 Mg _0.6 PS _4.7 Cl _0.8 Br _0.8 , and Li ₂ S powder, P ₂ S ₅ powder, LiCl powder, LiBr powder, The MgS powder is weighed so that the total amount becomes 5g. Heptane was added to the mixture of these powders, pulverized and mixed with a wet pulverizing and mixing ball mill for 10 hours, and then vacuum dried in a vacuum dryer to obtain raw material powders. After filling the obtained raw material powder into a carbon container (40mm×30mm×20mm, non-airtightness) to 80% by volume, hydrogen sulfide gas (H ₂ S) was circulated at 1.0 L/min through a tubular electric furnace. After heating at 300°C (product temperature) for 4 hours, then heating at 500°C (product temperature) for 4 hours to obtain a fired product. The temperature rise and fall speed is 200°C/hour. The obtained fired product was coarsely pulverized in a mortar, heptane was added, and the mixture was pulverized and mixed with a wet pulverizing and mixing ball mill for 3 hours, and then sized using a stainless steel mesh with a mesh of 1 μm to obtain a powdered sulfide solid electrolyte. . In addition, the additive element used in Example 1 is Mg (first free energy of Mg: 737.3 KJ/mol), and the ratio of the content of Mg to the content of Li is 0.125 in molar ratio.

The weighing, mixing, placing in the electric furnace, taking out from the electric furnace, disintegrating and sizing are all carried out in a glove box replaced with fully dried Ar gas (dew point below -60°C).

The composition of the obtained sulfide solid electrolyte was measured by ICP emission analysis method, and it was confirmed that the composition of the obtained sulfide solid electrolyte was Li _4.8 Mg _0.6 PS _4.7 Cl _0.8 Br _0.8 .

The result of analyzing the obtained sulfide solid electrolyte by X-ray diffraction (XRD) is shown in FIG. 1. In addition, the X-ray diffraction method uses the XRD device "RINT-TTRIII" manufactured by Rigaku Co., Ltd., scanning axis: 2θ/θ, scanning range: 5 to 80 deg, step width: 0.02 deg, scanning speed: 20 Under the condition of deg/min. Specifically, after dropping a few drops of liquid paraffin on the solid electrolyte powder in an argon atmosphere, the X-ray diffraction method is performed in the atmosphere.

(2) Measurement of the amount of hydrogen sulfide (H ₂ S) produced. Under an argon atmosphere, 50 mg of the sulfide solid electrolyte powder of Example 1 obtained in (1) above was weighed and placed in a closed container (volume 1750 cm ³ , Dew point -30℃, temperature 25℃ dry air). While the air in the closed container is circulated by an air pump, a hydrogen sulfide sensor (GX-2009 manufactured by Riken Keiki Co., Ltd.) is used to measure the amount of hydrogen sulfide produced. After the solid electrolyte powder was exposed to dry air for 1 hour, the volume of hydrogen sulfide generated was measured. In Table 1, the amount of hydrogen sulfide generated is expressed in terms of the value per unit mass of the solid electrolyte powder.

(3) Measurement of conductivity The sulfide solid electrolyte powder of Example 1 obtained in (1) above was subjected to uniaxial compression molding at a pressure of 200 MPa in a glove box replaced with a sufficiently dried Ar gas (dew point below -60°C) Then, pellets with a diameter of 10 mm and a thickness of 2 to 5 mm were produced, and carbon paste as electrodes was applied to both the top and bottom of the pellets, and then heat-treated at 180°C for 30 minutes to produce samples for ion conductivity measurement. The ionic conductivity (unit: S/cm) was measured at room temperature (25°C) using a device Solartron 1255B manufactured by Toyo Technical Co., under the conditions of a measurement frequency of 0.1 Hz to 1 MHz, and measured by the AC impedance method.

The results of Example 1 are shown in Table 1.

[Example 2] The _{total amount of Li 2} S powder, P ₂ S ₅ powder, LiCl powder, LiBr powder, and CaS powder will be 5 g in order to finally become the composition of _{Li 4.8} Ca _0.6 PS _4.7 Cl _0.8 Br _0.8 Except for this point, a powdered sulfide solid electrolyte was produced in the same manner as in Example 1, and the amount of hydrogen sulfide generated and the electrical conductivity were measured. In addition, the additive element used in Example 2 is Ca (the first free energy of Ca: 589.6 KJ/mol), and the ratio of the content of Ca to the content of Li is 0.125 in molar ratio.

The composition of the sulfide solid electrolyte obtained in Example 2 was measured by the ICP emission analysis method, and it was confirmed that the composition of the obtained sulfide solid electrolyte was Li _4.8 Ca _0.6 PS _4.7 Cl _0.8 Br _0.8 .

The result of X-ray diffraction (XRD) analysis of the sulfide solid electrolyte obtained in Example 2 is shown in FIG. 1. In addition, the XRD measurement conditions are the same as in Example 1.

The results of Example 2 are shown in Table 1.

[Example 3] In order to finally become the composition of _{Li 4.8} Ag _0.6 PS _4.4 Cl _0.8 Br _0.8 , the total amount of _{Li 2} S powder, P ₂ S ₅ powder, LiCl powder, LiBr powder, and Ag _{2 S powder will become} Except for this point, the 5g method was weighed. In the same manner as in Example 1, a powdered sulfide solid electrolyte was produced, and the amount of hydrogen sulfide generated and the electrical conductivity were measured. In addition, the additive element used in Example 3 is Ag (Ag first free energy: 731.0 KJ/mol), and the ratio of the content of Ag to the content of Li is 0.125 in molar ratio.

The composition of the sulfide solid electrolyte obtained in Example 3 was measured by ICP emission analysis, and it was confirmed that the composition of the obtained sulfide solid electrolyte was Li _4.8 Ag _0.6 PS _4.4 Cl _0.8 Br _0.8 .

The result of X-ray diffraction (XRD) analysis of the sulfide solid electrolyte obtained in Example 3 is shown in FIG. 1. In addition, the XRD measurement conditions are the same as in Example 1.

The results of Example 3 are shown in Table 1.

[Example 4] The _{total amount of Li 2} S powder, P ₂ S ₅ powder, LiCl powder, LiBr powder, and MgCl ₂ powder will be 5g in order to finally become the composition of _{Li 5.3} Mg _0.1 PS _4.4 Cl _0.9 Br _0.8 Except for this point, a powdered sulfide solid electrolyte was produced in the same manner as in Example 1, and the amount of hydrogen sulfide generated and the electrical conductivity were measured. In addition, the additive element used in Example 4 is Mg (Mg first free energy: 737.3 KJ/mol), and the ratio of the content of Mg to the content of Li is 0.019 in molar ratio.

The composition of the sulfide solid electrolyte obtained in Example 4 was measured by ICP emission analysis, and it was confirmed that the composition of the obtained sulfide solid electrolyte was Li _5.3 Mg _0.1 PS _4.4 Cl _0.9 Br _0.8 .

The result of X-ray diffraction (XRD) analysis of the sulfide solid electrolyte obtained in Example 4 is shown in FIG. 2. In addition, the XRD measurement conditions are the same as in Example 1.

The results of Example 4 are shown in Table 1.

[Example 5] The _{total amount of Li 2} S powder, P ₂ S ₅ powder, LiCl powder, LiBr powder, and CaCl ₂ powder will be 5g in order to finally become the composition of _{Li 5.3} Ca _0.1 PS _4.4 Cl _0.9 Br _0.8 Except for this point, a powdered sulfide solid electrolyte was produced in the same manner as in Example 1, and the amount of hydrogen sulfide generated and the electrical conductivity were measured. In addition, the additive element used in Example 5 is Ca (the first free energy of Ca: 589.6 KJ/mol), and the ratio of the content of Ca to the content of Li is 0.019 in molar ratio.

The composition of the sulfide solid electrolyte obtained in Example 5 was measured by ICP emission analysis, and it was confirmed that the composition of the obtained sulfide solid electrolyte was Li _5.3 Ca _0.1 PS _4.4 Cl _0.9 Br _0.8 .

The result of X-ray diffraction (XRD) analysis of the sulfide solid electrolyte obtained in Example 5 is shown in FIG. 2. In addition, the XRD measurement conditions are the same as in Example 1.

The results of Example 5 are shown in Table 1.

[Example 6] In order to finally become the composition of _{Li 5.3} Ag _0.1 PS _4.4 Cl _0.8 Br _{0.8 , the total amount of Li 2} S powder, P ₂ S ₅ powder, LiCl powder, LiBr powder, and AgCl powder will become 5 g Except for this point, a powdered sulfide solid electrolyte was produced in the same manner as in Example 1, and the amount of hydrogen sulfide generated and the electrical conductivity were measured. In addition, the additive element used in Example 6 is Ag (Ag first free energy: 731.0 KJ/mol), and the ratio of the content of Ag to the content of Li is 0.019 in molar ratio.

The composition of the sulfide solid electrolyte obtained in Example 6 was measured by ICP emission analysis, and it was confirmed that the composition of the obtained sulfide solid electrolyte was Li _5.3 Ag _0.1 PS _4.4 Cl _0.8 Br _0.8 .

The result of X-ray diffraction (XRD) analysis of the sulfide solid electrolyte obtained in Example 6 is shown in FIG. 2. In addition, the XRD measurement conditions are the same as in Example 1.

The results of Example 6 are shown in Table 1.

[Example 7] In order to finally become the composition of _{Li 5.3} Y _0.1 PS _4.5 Cl _0.8 Br _{0.8 , Li 2} S powder, P ₂ S ₅ powder, LiCl powder, LiBr powder, and Y ₂ S ₃ powder were combined in full Except for this point, it was weighed so that it was 5 g. In the same manner as in Example 1, a powdered sulfide solid electrolyte was produced, and the amount of hydrogen sulfide generated and the electrical conductivity were measured. In addition, the additive element used in Example 7 is Y (first free energy of Y: 615.6 KJ/mol), and the ratio of the content of Y to the content of Li is 0.019 in molar ratio.

The composition of the sulfide solid electrolyte obtained in Example 7 was measured by the ICP emission analysis method, and it was confirmed that the composition of the obtained sulfide solid electrolyte was Li _5.3 Y _0.1 PS _4.5 Cl _0.8 Br _0.8 .

The result of X-ray diffraction (XRD) analysis of the sulfide solid electrolyte obtained in Example 7 is shown in FIG. 2. In addition, the XRD measurement conditions are the same as in Example 1.

The results of Example 7 are shown in Table 1.

[Example 8] Except for the final composition of _{Li 5.7} Mg _0.1 PS _4.8 Cl _{1.3 , Li 2} S powder, P ₂ S ₅ powder, LiCl powder, and MgCl ₂ powder were combined so that the total amount would be 5 g. The point of weighing is that instead of hydrogen sulfide gas in the tubular electric furnace, it is changed to argon (Ar) gas at 0.5L/min, and the conductivity measurement is performed as follows. The rest is the same as in Example 1. Similarly, a powdered sulfide solid electrolyte was produced, and the amount of hydrogen sulfide generated and the electrical conductivity were measured. In addition, the additive element used in Example 8 is Mg (Mg first free energy: 737.3 KJ/mol), and the ratio of the content of Mg to the content of Li is 0.017 in terms of molar ratio.

The measurement of electrical conductivity is performed as follows. The sulfide solid electrolyte powder obtained in Example 8 was subjected to uniaxial compression molding ^{by applying a weight of about 6t/cm 2 in} a glove box replaced with sufficiently dry argon gas (dew point below -60°C) , Produce a sample for measuring the lithium ion conductivity of particles with a diameter of 10mm and a thickness of about 1mm to 8mm. The lithium ion conductivity was measured by the AC impedance method using Solartron 1255B manufactured by Toyang Technical Co., Ltd. at a temperature of 25°C, a frequency of 100 Hz to 1 MHz, and an amplitude of 100 mV.

The composition of the sulfide solid electrolyte obtained in Example 8 was measured by the ICP emission analysis method, and it was confirmed that the composition of the obtained sulfide solid electrolyte was Li _5.7 Mg _0.1 PS _4.8 Cl _1.3 .

The result of X-ray diffraction (XRD) analysis of the sulfide solid electrolyte obtained in Example 8 is shown in FIG. 4. In addition, the XRD measurement conditions are the same as in Example 1. As shown in Fig. 4, the sulfide solid electrolyte obtained in Example 8 was analyzed by X-ray diffraction (XRD). The result was the same as the sulfide solid electrolyte obtained in Examples 1 to 7. = 25.19˚±1.00˚, 29.62˚±1.00˚, 30.97˚±1.00˚, 44.37˚±1.00˚ and 47.22˚±1.00˚, there are peaks at positions. In addition, under the influence of small background intensity, peaks at 2θ=15.34˚±1.00˚ and 17.74˚±1.00˚ are also observed.

The results of Example 8 are shown in Table 2.

[Example 9] Except for the final composition of _{Li 5.2} Mg _0.6 PS _4.8 Cl _{1.8 , Li 2} S powder, P ₂ S ₅ powder, LiCl powder, and MgCl ₂ powder were combined so that the total amount would be 5 g. The point of weighing is that instead of hydrogen sulfide gas in the tubular electric furnace, it is changed to argon (Ar) gas at 0.5 L/min, and the measurement of electrical conductivity is performed in the same manner as in Example 8. The rest In the same manner as in Example 1, a powdered sulfide solid electrolyte was produced, and the amount of hydrogen sulfide generated and the electrical conductivity were measured. In addition, the additive element used in Example 9 is Mg (first free energy of Mg: 737.3 KJ/mol), and the ratio of the content of Mg to the content of Li is 0.115 in terms of molar ratio.

The composition of the sulfide solid electrolyte obtained in Example 9 was measured by the ICP emission analysis method, and it was confirmed that the composition of the obtained sulfide solid electrolyte was Li _5.2 Mg _0.6 PS _4.8 Cl _1.8 .

The result of X-ray diffraction (XRD) analysis of the sulfide solid electrolyte obtained in Example 9 is shown in FIG. 4. In addition, the XRD measurement conditions are the same as in Example 1. The sulfide solid electrolyte obtained in Example 9 was analyzed by X-ray diffraction (XRD), and the result was the same as the sulfide solid electrolyte obtained in Examples 1 to 7, at 2θ=25.19˚±1.00˚ , 29.62˚±1.00˚, 30.97˚±1.00˚, 44.37˚±1.00˚ and 47.22˚±1.00˚, there are peaks. In addition, under the influence of small background intensity, peaks at 2θ=15.34˚±1.00˚ and 17.74˚±1.00˚ are also observed.

The results of Example 9 are shown in Table 2.

[Example 10] Except for the final composition of _{Li 5.6} Mg _0.1 PS _4.8 Cl _{1.2 , Li 2} S powder, P ₂ S ₅ powder, LiCl powder, and MgCl ₂ powder were combined so that the total amount would be 5 g. The point of weighing is that instead of hydrogen sulfide gas in the tubular electric furnace, it is changed to argon (Ar) gas at 0.5 L/min, and the measurement of electrical conductivity is performed in the same manner as in Example 8. The rest In the same manner as in Example 1, a powdered sulfide solid electrolyte was produced, and the amount of hydrogen sulfide generated and the electrical conductivity were measured. In addition, the additive element used in Example 10 is Mg (first free energy of Mg: 737.3 KJ/mol), and the ratio of the content of Mg to the content of Li is 0.018 in molar ratio.

The composition of the sulfide solid electrolyte obtained in Example 10 was measured by the ICP emission analysis method, and it was confirmed that the composition of the obtained sulfide solid electrolyte was Li _5.6 Mg _0.1 PS _4.8 Cl _1.2 .

The result of X-ray diffraction (XRD) analysis of the sulfide solid electrolyte obtained in Example 10 is shown in FIG. 4. In addition, the XRD measurement conditions are the same as in Example 1. The sulfide solid electrolyte obtained in Example 10 was analyzed by X-ray diffraction (XRD). The result was the same as the sulfide solid electrolyte obtained in Examples 1 to 7, and the result was 2θ=25.19˚±1.00˚ , 29.62˚±1.00˚, 30.97˚±1.00˚, 44.37˚±1.00˚ and 47.22˚±1.00˚, there are peaks. In addition, under the influence of small background intensity, peaks at 2θ=15.34˚±1.00˚ and 17.74˚±1.00˚ are also observed.

The results of Example 10 are shown in Table 2.

[Comparative Example 1] _{Li 2} S powder, P ₂ S ₅ powder, LiCl powder, LiBr powder, Na ₂ S powder, and NaCl powder were combined to form the _{final composition of Li 4.8} Na _0.6 PS _4.4 Cl _0.8 Br _0.8 Except for this point, the total amount will be 5 g. Except for this, a powdered sulfide solid electrolyte was produced in the same manner as in Example 1, and the amount of hydrogen sulfide generated and the electrical conductivity were measured. In addition, the additive element used in Comparative Example 1 is Na (the first free energy of Na: 495.7 KJ/mol), and the ratio of the content of Na to the content of Li is 0.019 in molar ratio.

The composition of the sulfide solid electrolyte obtained in Comparative Example 1 was measured by ICP emission analysis, and it was confirmed that the composition of the obtained sulfide solid electrolyte was Li _4.8 Na _0.6 PS _4.4 Cl _0.8 Br _0.8 .

The result of X-ray diffraction (XRD) analysis of the sulfide solid electrolyte obtained in Comparative Example 1 is shown in FIG. 3. In addition, the XRD measurement conditions are the same as in Example 1.

The results of Comparative Example 1 are shown in Table 1.

[Comparative Example 2] The Li ₂ S powder, P ₂ S ₅ powder, LiCl powder, and LiBr powder were weighed so that the _{final composition of Li 5.4} PS _4.4 Cl _0.8 Br _{0.8 would be 5 g.} Except for this point, in the same manner as in Example 1, a powdered sulfide solid electrolyte was produced, and the amount of hydrogen sulfide generated and the electrical conductivity were measured. In addition, no additional elements were used in Comparative Example 2.

The composition of the sulfide solid electrolyte obtained in Comparative Example 2 was measured by the ICP emission analysis method, and it was confirmed that the composition of the obtained sulfide solid electrolyte was Li _5.4 PS _4.4 Cl _0.8 Br _0.8 .

The result of X-ray diffraction (XRD) analysis of the sulfide solid electrolyte obtained in Comparative Example 2 is shown in FIG. 3. In addition, the XRD measurement conditions are the same as in Example 1.

The results of Comparative Example 2 are shown in Table 1.

[Comparative Example 3] Except for the final _{composition of Li 5.8} PS _4.8 Cl _1.2 , the Li ₂ S powder, P ₂ S ₅ powder, and LiCl powder are weighed so that the total amount becomes 5 g. In the tubular electric furnace, instead of hydrogen sulfide gas, it was changed to argon (Ar) gas at 0.5 L/min, and the conductivity measurement was performed in the same manner as in Example 8, and the rest was the same as in Example 1. Ground, produce powdered sulfide solid electrolyte, and measure hydrogen sulfide generation and electrical conductivity. In addition, in Comparative Example 3, no additional elements were used.

The composition of the sulfide solid electrolyte obtained in Comparative Example 3 was measured by ICP emission analysis method, and it was confirmed that the composition of the obtained sulfide solid electrolyte was Li _5.8 PS _4.8 Cl _1.2 .

The result of X-ray diffraction (XRD) analysis of the sulfide solid electrolyte obtained in Comparative Example 3 is shown in FIG. 4. In addition, the XRD measurement conditions are the same as in Example 1. The result of analyzing the sulfide solid electrolyte obtained in Comparative Example 3 by X-ray diffraction (XRD) is the same as that of the sulfide solid electrolyte obtained in Comparative Examples 1 and 2, at 2θ=25.19˚±1.00˚ , 29.62˚±1.00˚, 30.97˚±1.00˚, 44.37˚±1.00˚ and 47.22˚±1.00˚, there are peaks. In addition, under the influence of small background intensity, peaks at 2θ=15.34˚±1.00˚ and 17.74˚±1.00˚ are also observed.

The results of Comparative Example 3 are shown in Table 2.

As shown in Tables 1 and 2, in Examples 1 to 10, phosphorus element, sulfur element, and halogen element are contained, and are included in the X-ray diffraction pattern measured using CuKα1 line, at 2θ=25.19˚±1.00˚ And in the sulfide solid electrolyte with the peak crystalline phase at the position of 29.62˚±1.00˚, the metal element with the first free energy of more than 520.2 KJ/mol and less than 1007.3 KJ/mol by adding a part of Li (Ag, Mg, Ca, Y) is substituted to maintain the lithium ion conductivity of the sulfide solid electrolyte before replacement, and at the same time, it can suppress the generation of hydrogen sulfide gas more than the sulfide solid electrolyte before replacement.

[Fig. 1] Fig. 1 is a diagram showing the X-ray diffraction pattern of the sulfide solid electrolyte produced in Examples 1 to 3. [Fig. 2] Fig. 2 is an illustration of X-ray diffraction patterns of sulfide solid electrolytes produced in Examples 4-7. [Fig. 3] Fig. 3 is a diagram showing the X-ray diffraction pattern of the sulfide solid electrolyte produced in Comparative Examples 1 and 2. [Fig. 4] Fig. 4 is a diagram showing the X-ray diffraction patterns of the sulfide solid electrolytes produced in Examples 8 to 10 and Comparative Example 3.

Claims (11)

A sulfide solid electrolyte, which is characterized by: Contains: lithium (Li) element, phosphorus (P) element, sulfur (S) element, at least one halogen (X) element, at least one metal with a first free energy greater than 520.2 KJ/mol and less than 1007.3 KJ/mol (M) element, and, In the X-ray diffraction pattern measured using CuKα1 line, there are peaks at 2θ= 25.19˚±1.00˚ and 29.62˚±1.00˚. The sulfide solid electrolyte according to claim 1, wherein the aforementioned at least one metal (M) element is at least one of silver (Ag) element, magnesium (Mg) element, calcium (Ca) element, and yttrium (Y) element . The sulfide solid electrolyte as described in claim 1 or 2, wherein The ratio of the content of the aforementioned lithium (Li) element to the content of the aforementioned phosphorus (P) element is 2.0 or more and 6.5 or less in molar ratio; The ratio of the content of the aforementioned sulfur (S) element to the content of the aforementioned phosphorus (P) element, calculated in molar ratio, is 4.0 or more and 5.5 or less; The ratio of the content of the aforementioned at least one halogen (X) element to the content of the aforementioned phosphorus (P) element is 0.50 or more and 2.2 or less in molar ratio; The ratio of the content of the aforementioned metal (M) element to the content of the aforementioned phosphorus (P) element exceeds 0 and is 2.0 or less in molar ratio. The sulfide solid electrolyte according to any one of claims 1 to 3, wherein: The ratio of the total content of the lithium (Li) element and the metal (M) element to the content of the phosphorus (P) element is 2.2 or more and 6.7 or less in molar ratio. The sulfide solid electrolyte according to any one of claims 1 to 4, wherein: The ratio of the content of the metal (M) element to the content of the lithium (Li) element is greater than 0 and 1.0 or less in molar ratio. The sulfide solid electrolyte according to any one of claims 1 to 5, wherein the at least one halogen (X) element is at least one of a chlorine (Cl) element and a bromine (Br) element. The sulfide solid electrolyte according to any one of claims 1 to 6, wherein it has a composition represented by the following formula: Li _a M _b PS _c X _d [where X is the aforementioned at least one halogen (X) element , M is the aforementioned at least one metal (M) element, a is 3.0 or more and 6.5 or less, b is more than 0 and 2.0 or less, c is 3.5 or more and 5.5 or less, and d is 0.50 or more and 3.0 or less]. The sulfide solid electrolyte described in any one of claims 1 to 7, wherein in the aforementioned X-ray diffraction pattern, 2θ= 15.34˚±1.00˚, 17.74˚±1.00˚, 30.97˚±1.00˚, 44.37˚±1.00˚, 47.22˚±1.00˚ and 51.70˚±1.00˚ have peak values at the selected positions. An electrode composite material, characterized in that it contains the sulfide solid electrolyte described in any one of claims 1 to 8 and an active material. A slurry characterized by containing the sulfide solid electrolyte described in any one of claims 1 to 8 and a dispersion medium. A battery comprising: a positive electrode layer, a negative electrode layer, and a solid electrolyte layer located between the positive electrode layer and the negative electrode layer, wherein: The aforementioned solid electrolyte layer contains the sulfide solid electrolyte described in any one of claims 1 to 8.

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